Professional and Biographical Information
Degrees and Training
Postdoctoral Fellow, Section on Environmental Gene Regulation, National Institutes of Health (2016-2020)
Ph.D., Biological Sciences, University of Maryland, College Park (2010-2016)
B.A., Biology, Johns Hopkins University (2003-2007)
The strong critical thinking skills gained through the study of biological systems will allow students to thrive regardless of the field they ultimately choose. I am excited to introduce students to the world of molecular biology in Molecules, Genes, and Cells, and to share my enthusiasm for the diverse biological molecules and reactions that allow life to happen in Biochemistry.
Small things are fascinating! Among the smallest living organisms are bacteria, unicellular organisms that have a lot to teach us about resilience and responding to stress. Bacteria use a wide range of strategies to survive rapidly changing and often stressful environments. One mechanism is to synthesize specific small proteins (~50 amino acids or shorter). In bacteria and across all domains of life, small proteins are often made in response to sensing a stress condition. While these tiny proteins were previously ignored by traditional bioinformatic and biochemical assays, it is becoming clear that they comprise an under-appreciated class of important cellular regulators. However, very few small proteins have been mechanistically characterized and the full extent of the small proteome remains unknown.
I am interested in how bacterial small proteins mediate responses to environmental stresses, particularly antibiotic exposure. My lab uses a combination of biochemistry and genetics techniques to characterize a small protein that regulates an antibiotic efflux pump and to identify novel small proteins from bacterial pathogens. A better understanding of how these small proteins work will let us exploit their regulatory activities for the treatment of bacterial infections. Additionally, the lessons learned from these experiments will be valuable in the study of small proteins in other bacterial and eukaryotic species.
- Orr MW, Mao Y, Storz G, Qian SB. (2019) “Alternative ORFs and small ORFs: shedding light on the dark proteome.” Nucleic Acids Research. 48(3): 1029-1042. (Invited review)
- Yin X*, Orr MW*, Wang H, Hobbs HC, Storz G. (2019) “The small protein MgtS and small RNA MgrR modulate the PitA phosphate symporter to boost intracellular magnesium levels.” Molecular Microbiology 111(1): 131-144.
- Orr MW, Weiss CA, Severin GB, Turdiev H, Kim SK, Liu K, Tu BP, Waters CM, Winkler WC, Lee VT. (2018) “A subset of exoribonucleases serve as degradative enzymes for pGpG in c-di-GMP signaling.” Journal of Bacteriology 200(24): e00300-18.
- Orr MW, Donaldson GP, Severin GB, Wang J, Sintim HO, Waters CM, Lee VT. (2015) “Oligoribonuclease is the primary degradative enzyme for pGpG in Pseudomonas aeruginosa that is required for cyclic-di-GMP turnover.” Proceedings of the National Academy of Sciences U. S. A. 112(36): E5048-5057.
A complete list of published works is available in my bibliography